The primary objective of this research is to understand central integrative mechanisms in cortical regions of the vertebrate brain. The structures of the olfactory pathway - olfactory bulb and olfactory cortex - offer advantageous models for this purpose. Electrophysiological analysis of unitary activity in the salamander bulb has provided evidence for excitatory and inhibitory types of responses to step pulses of odor, delivered through a special olfactometer. These responses are being compared with those of olfactory receptors, to try to identify the specific steps in odor processing at these levels. Studies of 2-deoxy-glucose uptake are providing evidence of local sites of activity in the rat olfactory bulb related to specific odors. Collaborative biochemical studies are aimed at laminar localization of dopamine-sensitive adenylate cyclase in the rat olfactory tubercle.